package com.liruilong.fileserver.common.util;

import com.liruilong.fileserver.common.aop.FileLogAspect;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;


import javax.servlet.http.HttpServletRequest;
import java.net.*;
import java.util.Enumeration;

/**
 * @author Liruilong
 * @Date 2020/9/14 16:08
 * @Description:
 */
public class IpUtil {

    /**
     * 获取IP地址
     *
     * 使用Nginx等反向代理软件， 则不能通过request.getRemoteAddr()获取IP地址
     * 如果使用了多级反向代理的话，X-Forwarded-For的值并不止一个，而是一串IP地址，X-Forwarded-For中第一个非unknown的有效IP字符串，则为真实IP地址
     */
    private static Logger logger4j = LoggerFactory.getLogger(IpUtil.class);
        private static final String LOCAL_IP = "127.0.0.1";
        /**
         * 获取IP地址
         *
         * 使用Nginx等反向代理软件， 则不能通过request.getRemoteAddr()获取IP地址
         * 如果使用了多级反向代理的话，X-Forwarded-For的值并不止一个，而是一串IP地址，X-Forwarded-For中第一个非unknown的有效IP字符串，则为真实IP地址
         */
        public static String getIpAddr(HttpServletRequest request) {
            if (request == null) {
                return "unknown";
            }
            String ip = request.getHeader("x-forwarded-for");
            if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
                ip = request.getHeader("Proxy-Client-IP");
            }
            if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
                ip = request.getHeader("X-Forwarded-For");
            }
            if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
                ip = request.getHeader("WL-Proxy-Client-IP");
            }
            if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
                ip = request.getHeader("X-Real-IP");
            }

            if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
                ip = request.getRemoteAddr();
            }

            return "0:0:0:0:0:0:0:1".equals(ip) ? LOCAL_IP : ip;
        }

        public static boolean internalIp(String ip) {
            boolean res = false;
            byte[] addr = textToNumericFormatV4(ip);
            if (addr != null && ip != null) {
                res = internalIp(addr) || LOCAL_IP.equals(ip);
            }
            return res;
        }

        private static boolean internalIp(byte[] addr) {
            final byte b0 = addr[0];
            final byte b1 = addr[1];
            // 10.x.x.x/8
            final byte SECTION_1 = 0x0A;
            // 172.16.x.x/12
            final byte SECTION_2 = (byte) 0xAC;
            final byte SECTION_3 = (byte) 0x10;
            final byte SECTION_4 = (byte) 0x1F;
            // 192.168.x.x/16
            final byte SECTION_5 = (byte) 0xC0;
            final byte SECTION_6 = (byte) 0xA8;
            boolean flag = false;
            switch (b0) {
                case SECTION_1:
                    flag = true;
                    break;
                case SECTION_2:
                    if (b1 >= SECTION_3 && b1 <= SECTION_4) {
                        flag = true;
                    }
                    break;
                case SECTION_5:
                    if (b1 == SECTION_6) {
                        flag = true;
                    }
                    break;
                default:
                    break;
            }
            return flag;
        }

        /**
         * 将IPv4地址转换成字节
         *IPv4地址
         * @param text
         * @return byte 字节
         */
        public static byte[] textToNumericFormatV4(String text) {
            if (text.length() == 0) {
                return null;
            }

            byte[] bytes = new byte[4];
            String[] elements = text.split("\\.", -1);
            try {
                long l;
                int i;
                switch (elements.length) {
                    case 1:
                        l = Long.parseLong(elements[0]);
                        if ((l < 0L) || (l > 4294967295L))
                            return null;
                        bytes[0] = (byte) (int) (l >> 24 & 0xFF);
                        bytes[1] = (byte) (int) ((l & 0xFFFFFF) >> 16 & 0xFF);
                        bytes[2] = (byte) (int) ((l & 0xFFFF) >> 8 & 0xFF);
                        bytes[3] = (byte) (int) (l & 0xFF);
                        break;
                    case 2:
                        l = Integer.parseInt(elements[0]);
                        if ((l < 0L) || (l > 255L))
                            return null;
                        bytes[0] = (byte) (int) (l & 0xFF);
                        l = Integer.parseInt(elements[1]);
                        if ((l < 0L) || (l > 16777215L))
                            return null;
                        bytes[1] = (byte) (int) (l >> 16 & 0xFF);
                        bytes[2] = (byte) (int) ((l & 0xFFFF) >> 8 & 0xFF);
                        bytes[3] = (byte) (int) (l & 0xFF);
                        break;
                    case 3:
                        for (i = 0; i < 2; ++i) {
                            l = Integer.parseInt(elements[i]);
                            if ((l < 0L) || (l > 255L))
                                return null;
                            bytes[i] = (byte) (int) (l & 0xFF);
                        }
                        l = Integer.parseInt(elements[2]);
                        if ((l < 0L) || (l > 65535L))
                            return null;
                        bytes[2] = (byte) (int) (l >> 8 & 0xFF);
                        bytes[3] = (byte) (int) (l & 0xFF);
                        break;
                    case 4:
                        for (i = 0; i < 4; ++i) {
                            l = Integer.parseInt(elements[i]);
                            if ((l < 0L) || (l > 255L))
                                return null;
                            bytes[i] = (byte) (int) (l & 0xFF);
                        }
                        break;
                    default:
                        return null;
                }
            } catch (NumberFormatException e) {
                logger4j.error("数字格式化异常",e);
                return null;
            }
            return bytes;
        }

        public static String getLocalIP() {
            String ip = "";
            if (System.getProperty("os.name").toLowerCase().startsWith("windows")) {
                InetAddress addr;
                try {
                    addr = InetAddress.getLocalHost();
                    ip = addr.getHostAddress();
                } catch (UnknownHostException e) {
                    logger4j.error("获取失败",e);
                }
                return ip;
            } else {
                try {
                    Enumeration<?> e1 = (Enumeration<?>) NetworkInterface
                            .getNetworkInterfaces();
                    while (e1.hasMoreElements()) {
                        NetworkInterface ni = (NetworkInterface) e1.nextElement();
                        if (!ni.getName().equals("eth0")) {
                            continue;
                        } else {
                            Enumeration<?> e2 = ni.getInetAddresses();
                            while (e2.hasMoreElements()) {
                                InetAddress ia = (InetAddress) e2.nextElement();
                                if (ia instanceof Inet6Address)
                                    continue;
                                ip = ia.getHostAddress();
                                return ip;
                            }
                            break;
                        }
                    }
                } catch (SocketException e) {
                    logger4j.error("获取失败",e);
                }
            }
            return "";
        }
    }

